function initTD() {
	dojo.declare("TDTAnnoLayer", esri.layers.TiledMapServiceLayer, {
		constructor: function() { // map_type: img_c|vec_c
			this.map_type = 'vec_c';
			this.spatialReference = new esri.SpatialReference({
				wkid: 4326
			});
			this.fullExtent = new esri.geometry.Extent(-180.0, -90.0, 180.0,
				90.0, this.spatialReference);
			this.tileInfo = new esri.layers.TileInfo({
				"rows": 256,
				"cols": 256,
				"compressionQuality": 0,
				"origin": {
					"x": -180,
					"y": 90
				},
				"spatialReference": {
					"wkid": 4326
				},
				"lods": [{
					"level": 1,
					"resolution": 0.3515625,
					"scale": 147748799.285417
				}, {
					"level": 2,
					"resolution": 0.17578125,
					"scale": 73874399.6427087
				}, {
					"level": 3,
					"resolution": 0.087890625,
					"scale": 36937199.8213544
				}, {
					"level": 4,
					"resolution": 0.0439453125,
					"scale": 18468599.9106772
				}, {
					"level": 5,
					"resolution": 0.02197265625,
					"scale": 9234299.95533859
				}, {
					"level": 6,
					"resolution": 0.010986328125,
					"scale": 4617149.97766929
				}, {
					"level": 7,
					"resolution": 0.0054931640625,
					"scale": 2308574.98883465
				}, {
					"level": 8,
					"resolution": 0.00274658203125,
					"scale": 1154287.49441732
				}, {
					"level": 9,
					"resolution": 0.001373291015625,
					"scale": 577143.747208662
				}, {
					"level": 10,
					"resolution": 0.0006866455078125,
					"scale": 288571.873604331
				}, {
					"level": 11,
					"resolution": 0.00034332275390625,
					"scale": 144285.936802165
				}, {
					"level": 12,
					"resolution": 0.000171661376953125,
					"scale": 72142.9684010827
				}, {
					"level": 13,
					"resolution": 8.58306884765629E-05,
					"scale": 36071.4842005414
				}, {
					"level": 14,
					"resolution": 4.29153442382814E-05,
					"scale": 18035.7421002707
				}, {
					"level": 15,
					"resolution": 2.14576721191407E-05,
					"scale": 9017.87105013534
				}]
			});

			this.loaded = true;
			this.onLoad(this);
		},

		getTileUrl: function(level, row, col) {
			return "http://t0.tianditu.com/DataServer?T=" + this.map_type + "&" + "X=" + col + "&" + "Y=" + row + "&" + "L=" + (level * 1 + 1);
		}
	});
}